The formation energy of Si donors, acceptors, and defect complexes were calculated. The equilibrium concentrations of native defects and Si-defect complexes were deduced from these energies, as was the total solubility of Si. The calculated equilibrium solubility limit for Si was in good agreement with experimental data. The (SiGa-VGa)2- complex occurred at relatively high concentrations under As-rich conditions, and could therefore mediate Si and Ga diffusion. It was concluded that the donor-vacancy complex was an important compensation mechanism in heavily doped GaAs.

J.E.Northrup, S.B.Zhang: Physical Review B, 1993, 47[11], 6791-4